Genetics and Tiredness: Is Feeling Exhausted in Your DNA?
If you frequently feel drained or low in energy, your genes may be playing a small but measurable role. New research published in Springer Nature’s journal Molecular Psychiatry has found a meaningful connection between genetics and tiredness, confirming that hereditary factors account for approximately 8 percent of the variation in how people self report fatigue and low energy levels.
The study was led by Vincent Deary of Northumbria University and Saskia Hagenaars of the University of Edinburgh, and drew on genetic data from 111,749 participants in the UK Biobank, one of the largest biomedical databases in the world. Participants reported whether they had experienced tiredness or low energy in the two weeks prior to data collection. Researchers then conducted genome wide association analyses, heritability estimates, and genetic overlap testing across more than 25 health related variables.
What the Research Found About Genetics and Tiredness
The most significant takeaway is that while genetics and tiredness are genuinely connected, the relationship is complex and multidirectional. The genetic factors associated with tiredness did not operate in isolation. Instead, they overlapped substantially with genetic predispositions to a range of mental and physical health conditions, including depression, schizophrenia, metabolic syndrome, obesity, and reduced grip strength.
Importantly, the researchers found that it was genetic proneness to illness, not just the presence of diagnosed conditions, that correlated with tiredness. For example, participants who were genetically predisposed to diabetes but had not developed the condition still showed the small genetic link to fatigue. This suggests that underlying biological vulnerabilities, rather than disease itself, may be part of what connects genetics and tiredness at a molecular level.
3 Key Genetic Overlaps Identified
The study identified several specific areas where genetics and tiredness intersect in clinically relevant ways.
Metabolic syndrome and physiological stress. Participants with a higher genetic tendency toward metabolic syndrome markers, including elevated cholesterol, high waist to hip ratio, and obesity, were more likely to report tiredness. Researchers noted this raises the possibility of a genetic link between fatigue and vulnerability to physiological stress, a connection with broad implications for how chronic fatigue is understood and treated.
Mental health conditions. Genetic associations were found between tiredness and depression, as well as schizophrenia. People with a greater tendency to experience mental and emotional distress were more likely to report persistent fatigue, reinforcing the well established clinical relationship between mood disorders and energy levels.
Longevity and lifestyle factors. The research also identified a genetic association between tiredness and longevity, as well as smoking behavior. These findings suggest that tiredness proneness may be part of a broader genetic profile influencing long term health outcomes and behavioral patterns.
Most of Tiredness Is Still Environmental
Despite the clear signal between genetics and tiredness, the research team was careful to emphasize that the vast majority of differences in fatigue among individuals, approximately 91 to 92 percent, are likely environmental in origin. Factors such as sleep quality, stress, diet, physical activity, and underlying health conditions remain the dominant drivers of how tired people feel on a day to day basis.
Hagenaars summarized this balance clearly: being genetically predisposed to a range of mental and physical health complaints also predisposes people to report greater tiredness or lack of energy, but genetics alone does not determine fatigue. For a comprehensive look at fatigue causes and when to seek medical evaluation, the Mayo Clinic offers a thorough overview.
Clinical Research Into Fatigue and Metabolic Health
The genetic overlaps identified in this study, particularly those involving metabolic syndrome and mental health, underscore the importance of continued clinical investigation into fatigue as a symptom with biological roots. Understanding those roots more precisely could lead to better diagnostic tools and more targeted interventions.
FOMAT supports clinical research across endocrinology, metabolic conditions, and related therapeutic areas. To explore active studies, visit our patient active studies page. For more health and research insights, explore the FOMAT blogs and updates.